Have you tried to contact owner of website?
No means,Try to contact immediately.It's one of the best way to know the reason for banned.
Sometimes,they restricted some range of ip address,There may be a chance your ip address range is match to the restricted ip range.So only you got banned message.If your problem presist after contact your owner means,try to change your ip address by using using the hide ip application,It's one of the best way to bypass your web restrictions.
After using hide application,You can check your new ip using Ip-Details.com